fs/proc/task_nommu.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0

 #include <linux/mm.h>
 #include <linux/file.h>
 #include <linux/fdtable.h>
 #include <linux/fs_struct.h>
 #include <linux/mount.h>
 #include <linux/ptrace.h>
 #include <linux/slab.h>
 #include <linux/seq_file.h>
 #include <linux/sched/mm.h>

 #include "internal.h"

 /*
  * Logic: we've got two memory sums for each process, "shared", and
  * "non-shared". Shared memory may get counted more than once, for
  * each process that owns it. Non-shared memory is counted
  * accurately.
  */
 void task_mem(struct seq_file *m, struct mm_struct *mm)
 {
 	VMA_ITERATOR(vmi, mm, 0);
 	struct vm_area_struct *vma;
 	struct vm_region *region;
 	unsigned long bytes = 0, sbytes = 0, slack = 0, size;

 	mmap_read_lock(mm);
 	for_each_vma(vmi, vma) {
 		bytes += kobjsize(vma);

 		region = vma->vm_region;
 		if (region) {
 			size = kobjsize(region);
 			size += region->vm_end - region->vm_start;
 		} else {
 			size = vma->vm_end - vma->vm_start;
 		}

 		if (atomic_read(&mm->mm_count) > 1 ||
 		    vma->vm_flags & VM_MAYSHARE) {
 			sbytes += size;
 		} else {
 			bytes += size;
 			if (region)
 				slack = region->vm_end - vma->vm_end;
 		}
 	}

 	if (atomic_read(&mm->mm_count) > 1)
 		sbytes += kobjsize(mm);
 	else
 		bytes += kobjsize(mm);

 	if (current->fs && current->fs->users > 1)
 		sbytes += kobjsize(current->fs);
 	else
 		bytes += kobjsize(current->fs);

 	if (current->files && atomic_read(&current->files->count) > 1)
 		sbytes += kobjsize(current->files);
 	else
 		bytes += kobjsize(current->files);

 	if (current->sighand && refcount_read(&current->sighand->count) > 1)
 		sbytes += kobjsize(current->sighand);
 	else
 		bytes += kobjsize(current->sighand);

 	bytes += kobjsize(current); /* includes kernel stack */

 	seq_printf(m,
 		"Mem:\t%8lu bytes\n"
 		"Slack:\t%8lu bytes\n"
 		"Shared:\t%8lu bytes\n",
 		bytes, slack, sbytes);

 	mmap_read_unlock(mm);
 }

 unsigned long task_vsize(struct mm_struct *mm)
 {
 	VMA_ITERATOR(vmi, mm, 0);
 	struct vm_area_struct *vma;
 	unsigned long vsize = 0;

 	mmap_read_lock(mm);
 	for_each_vma(vmi, vma)
 		vsize += vma->vm_end - vma->vm_start;
 	mmap_read_unlock(mm);
 	return vsize;
 }

 unsigned long task_statm(struct mm_struct *mm,
 			 unsigned long *shared, unsigned long *text,
 			 unsigned long *data, unsigned long *resident)
 {
 	VMA_ITERATOR(vmi, mm, 0);
 	struct vm_area_struct *vma;
 	struct vm_region *region;
 	unsigned long size = kobjsize(mm);

 	mmap_read_lock(mm);
 	for_each_vma(vmi, vma) {
 		size += kobjsize(vma);
 		region = vma->vm_region;
 		if (region) {
 			size += kobjsize(region);
 			size += region->vm_end - region->vm_start;
 		}
 	}

 	*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
 		>> PAGE_SHIFT;
 	*data = (PAGE_ALIGN(mm->start_stack) - (mm->start_data & PAGE_MASK))
 		>> PAGE_SHIFT;
 	mmap_read_unlock(mm);
 	size >>= PAGE_SHIFT;
 	size += *text + *data;
 	*resident = size;
 	return size;
 }

 static int is_stack(struct vm_area_struct *vma)
 {
 	struct mm_struct *mm = vma->vm_mm;

 	/*
 	 * We make no effort to guess what a given thread considers to be
 	 * its "stack".  It's not even well-defined for programs written
 	 * languages like Go.
 	 */
 	return vma->vm_start <= mm->start_stack &&
 		vma->vm_end >= mm->start_stack;
 }

 /*
  * display a single VMA to a sequenced file
  */
 static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma)
 {
 	struct mm_struct *mm = vma->vm_mm;
 	unsigned long ino = 0;
 	struct file *file;
 	dev_t dev = 0;
 	int flags;
 	unsigned long long pgoff = 0;

 	flags = vma->vm_flags;
 	file = vma->vm_file;

 	if (file) {
 		struct inode *inode = file_inode(vma->vm_file);
 		dev = inode->i_sb->s_dev;
 		ino = inode->i_ino;
 		pgoff = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
 	}

 	seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
 	seq_printf(m,
 		   "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ",
 		   vma->vm_start,
 		   vma->vm_end,
 		   flags & VM_READ ? 'r' : '-',
 		   flags & VM_WRITE ? 'w' : '-',
 		   flags & VM_EXEC ? 'x' : '-',
 		   flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',
 		   pgoff,
 		   MAJOR(dev), MINOR(dev), ino);

 	if (file) {
 		seq_pad(m, ' ');
 		seq_file_path(m, file, "");
 	} else if (mm && is_stack(vma)) {
 		seq_pad(m, ' ');
 		seq_puts(m, "[stack]");
 	}

 	seq_putc(m, '\n');
 	return 0;
 }

 /*
  * display mapping lines for a particular process's /proc/pid/maps
  */
 static int show_map(struct seq_file *m, void *_p)
 {
 	return nommu_vma_show(m, _p);
 }

 static struct vm_area_struct *proc_get_vma(struct proc_maps_private *priv,
 						loff_t *ppos)
 {
 	struct vm_area_struct *vma = vma_next(&priv->iter);

 	if (vma) {
 		*ppos = vma->vm_start;
 	} else {
 		*ppos = -1UL;
 	}

 	return vma;
 }

 static void *m_start(struct seq_file *m, loff_t *ppos)
 {
 	struct proc_maps_private *priv = m->private;
 	unsigned long last_addr = *ppos;
 	struct mm_struct *mm;

 	/* See proc_get_vma(). Zero at the start or after lseek. */
 	if (last_addr == -1UL)
 		return NULL;

 	/* pin the task and mm whilst we play with them */
 	priv->task = get_proc_task(priv->inode);
 	if (!priv->task)
 		return ERR_PTR(-ESRCH);

 	mm = priv->mm;
 	if (!mm || !mmget_not_zero(mm)) {
 		put_task_struct(priv->task);
 		priv->task = NULL;
 		return NULL;
 	}

 	if (mmap_read_lock_killable(mm)) {
 		mmput(mm);
 		put_task_struct(priv->task);
 		priv->task = NULL;
 		return ERR_PTR(-EINTR);
 	}

 	vma_iter_init(&priv->iter, mm, last_addr);

 	return proc_get_vma(priv, ppos);
 }

 static void m_stop(struct seq_file *m, void *v)
 {
 	struct proc_maps_private *priv = m->private;
 	struct mm_struct *mm = priv->mm;

 	if (!priv->task)
 		return;

 	mmap_read_unlock(mm);
 	mmput(mm);
 	put_task_struct(priv->task);
 	priv->task = NULL;
 }

 static void *m_next(struct seq_file *m, void *_p, loff_t *ppos)
 {
 	return proc_get_vma(m->private, ppos);
 }

 static const struct seq_operations proc_pid_maps_ops = {
 	.start	= m_start,
 	.next	= m_next,
 	.stop	= m_stop,
 	.show	= show_map
 };

 static int maps_open(struct inode *inode, struct file *file,
 		     const struct seq_operations *ops)
 {
 	struct proc_maps_private *priv;

 	priv = __seq_open_private(file, ops, sizeof(*priv));
 	if (!priv)
 		return -ENOMEM;

 	priv->inode = inode;
 	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
 	if (IS_ERR(priv->mm)) {
 		int err = PTR_ERR(priv->mm);

 		seq_release_private(inode, file);
 		return err;
 	}

 	return 0;
 }


 static int map_release(struct inode *inode, struct file *file)
 {
 	struct seq_file *seq = file->private_data;
 	struct proc_maps_private *priv = seq->private;

 	if (priv->mm)
 		mmdrop(priv->mm);

 	return seq_release_private(inode, file);
 }

 static int pid_maps_open(struct inode *inode, struct file *file)
 {
 	return maps_open(inode, file, &proc_pid_maps_ops);
 }

 const struct file_operations proc_pid_maps_operations = {
 	.open		= pid_maps_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
 	.release	= map_release,
 };
	// SPDX-License-Identifier: GPL-2.0

	#include <linux/mm.h>
	#include <linux/file.h>
	#include <linux/fdtable.h>
	#include <linux/fs_struct.h>
	#include <linux/mount.h>
	#include <linux/ptrace.h>
	#include <linux/slab.h>
	#include <linux/seq_file.h>
	#include <linux/sched/mm.h>

	#include "internal.h"

	/*
	* Logic: we've got two memory sums for each process, "shared", and
	* "non-shared". Shared memory may get counted more than once, for
	* each process that owns it. Non-shared memory is counted
	* accurately.
	*/
	void task_mem(struct seq_file m, struct mm_struct mm)
	{
	VMA_ITERATOR(vmi, mm, 0);
	struct vm_area_struct *vma;
	struct vm_region *region;
	unsigned long bytes = 0, sbytes = 0, slack = 0, size;

	mmap_read_lock(mm);
	for_each_vma(vmi, vma) {
	bytes += kobjsize(vma);

	region = vma->vm_region;
	if (region) {
	size = kobjsize(region);
	size += region->vm_end - region->vm_start;
	} else {
	size = vma->vm_end - vma->vm_start;
	}

	if (atomic_read(&mm->mm_count) > 1 \|\|
	vma->vm_flags & VM_MAYSHARE) {
	sbytes += size;
	} else {
	bytes += size;
	if (region)
	slack = region->vm_end - vma->vm_end;
	}
	}

	if (atomic_read(&mm->mm_count) > 1)
	sbytes += kobjsize(mm);
	else
	bytes += kobjsize(mm);

	if (current->fs && current->fs->users > 1)
	sbytes += kobjsize(current->fs);
	else
	bytes += kobjsize(current->fs);

	if (current->files && atomic_read(&current->files->count) > 1)
	sbytes += kobjsize(current->files);
	else
	bytes += kobjsize(current->files);

	if (current->sighand && refcount_read(&current->sighand->count) > 1)
	sbytes += kobjsize(current->sighand);
	else
	bytes += kobjsize(current->sighand);

	bytes += kobjsize(current); /* includes kernel stack */

	seq_printf(m,
	"Mem:\t%8lu bytes\n"
	"Slack:\t%8lu bytes\n"
	"Shared:\t%8lu bytes\n",
	bytes, slack, sbytes);

	mmap_read_unlock(mm);
	}

	unsigned long task_vsize(struct mm_struct *mm)
	{
	VMA_ITERATOR(vmi, mm, 0);
	struct vm_area_struct *vma;
	unsigned long vsize = 0;

	mmap_read_lock(mm);
	for_each_vma(vmi, vma)
	vsize += vma->vm_end - vma->vm_start;
	mmap_read_unlock(mm);
	return vsize;
	}

	unsigned long task_statm(struct mm_struct *mm,
	unsigned long shared, unsigned long text,
	unsigned long data, unsigned long resident)
	{
	VMA_ITERATOR(vmi, mm, 0);
	struct vm_area_struct *vma;
	struct vm_region *region;
	unsigned long size = kobjsize(mm);

	mmap_read_lock(mm);
	for_each_vma(vmi, vma) {
	size += kobjsize(vma);
	region = vma->vm_region;
	if (region) {
	size += kobjsize(region);
	size += region->vm_end - region->vm_start;
	}
	}

	*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
	>> PAGE_SHIFT;
	*data = (PAGE_ALIGN(mm->start_stack) - (mm->start_data & PAGE_MASK))
	>> PAGE_SHIFT;
	mmap_read_unlock(mm);
	size >>= PAGE_SHIFT;
	size += text + data;
	*resident = size;
	return size;
	}

	static int is_stack(struct vm_area_struct *vma)
	{
	struct mm_struct *mm = vma->vm_mm;

	/*
	* We make no effort to guess what a given thread considers to be
	* its "stack". It's not even well-defined for programs written
	* languages like Go.
	*/
	return vma->vm_start <= mm->start_stack &&
	vma->vm_end >= mm->start_stack;
	}

	/*
	* display a single VMA to a sequenced file
	*/
	static int nommu_vma_show(struct seq_file m, struct vm_area_struct vma)
	{
	struct mm_struct *mm = vma->vm_mm;
	unsigned long ino = 0;
	struct file *file;
	dev_t dev = 0;
	int flags;
	unsigned long long pgoff = 0;

	flags = vma->vm_flags;
	file = vma->vm_file;

	if (file) {
	struct inode *inode = file_inode(vma->vm_file);
	dev = inode->i_sb->s_dev;
	ino = inode->i_ino;
	pgoff = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
	}

	seq_setwidth(m, 25 + sizeof(void ) 6 - 1);
	seq_printf(m,
	"%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ",
	vma->vm_start,
	vma->vm_end,
	flags & VM_READ ? 'r' : '-',
	flags & VM_WRITE ? 'w' : '-',
	flags & VM_EXEC ? 'x' : '-',
	flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',
	pgoff,
	MAJOR(dev), MINOR(dev), ino);

	if (file) {
	seq_pad(m, ' ');
	seq_file_path(m, file, "");
	} else if (mm && is_stack(vma)) {
	seq_pad(m, ' ');
	seq_puts(m, "[stack]");
	}

	seq_putc(m, '\n');
	return 0;
	}

	/*
	* display mapping lines for a particular process's /proc/pid/maps
	*/
	static int show_map(struct seq_file m, void _p)
	{
	return nommu_vma_show(m, _p);
	}

	static struct vm_area_struct proc_get_vma(struct proc_maps_private priv,
	loff_t *ppos)
	{
	struct vm_area_struct *vma = vma_next(&priv->iter);

	if (vma) {
	*ppos = vma->vm_start;
	} else {
	*ppos = -1UL;
	}

	return vma;
	}

	static void m_start(struct seq_file m, loff_t *ppos)
	{
	struct proc_maps_private *priv = m->private;
	unsigned long last_addr = *ppos;
	struct mm_struct *mm;

	/* See proc_get_vma(). Zero at the start or after lseek. */
	if (last_addr == -1UL)
	return NULL;

	/* pin the task and mm whilst we play with them */
	priv->task = get_proc_task(priv->inode);
	if (!priv->task)
	return ERR_PTR(-ESRCH);

	mm = priv->mm;
	if (!mm \|\| !mmget_not_zero(mm)) {
	put_task_struct(priv->task);
	priv->task = NULL;
	return NULL;
	}

	if (mmap_read_lock_killable(mm)) {
	mmput(mm);
	put_task_struct(priv->task);
	priv->task = NULL;
	return ERR_PTR(-EINTR);
	}

	vma_iter_init(&priv->iter, mm, last_addr);

	return proc_get_vma(priv, ppos);
	}

	static void m_stop(struct seq_file m, void v)
	{
	struct proc_maps_private *priv = m->private;
	struct mm_struct *mm = priv->mm;

	if (!priv->task)
	return;

	mmap_read_unlock(mm);
	mmput(mm);
	put_task_struct(priv->task);
	priv->task = NULL;
	}

	static void m_next(struct seq_file m, void _p, loff_t ppos)
	{
	return proc_get_vma(m->private, ppos);
	}

	static const struct seq_operations proc_pid_maps_ops = {
	.start = m_start,
	.next = m_next,
	.stop = m_stop,
	.show = show_map
	};

	static int maps_open(struct inode inode, struct file file,
	const struct seq_operations *ops)
	{
	struct proc_maps_private *priv;

	priv = __seq_open_private(file, ops, sizeof(*priv));
	if (!priv)
	return -ENOMEM;

	priv->inode = inode;
	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
	if (IS_ERR(priv->mm)) {
	int err = PTR_ERR(priv->mm);

	seq_release_private(inode, file);
	return err;
	}

	return 0;
	}


	static int map_release(struct inode inode, struct file file)
	{
	struct seq_file *seq = file->private_data;
	struct proc_maps_private *priv = seq->private;

	if (priv->mm)
	mmdrop(priv->mm);

	return seq_release_private(inode, file);
	}

	static int pid_maps_open(struct inode inode, struct file file)
	{
	return maps_open(inode, file, &proc_pid_maps_ops);
	}

	const struct file_operations proc_pid_maps_operations = {
	.open = pid_maps_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = map_release,
	};